On Sat, May 24, 2025, 7:46 AM Serhat Rıfat Demircan <
[email protected]> wrote:

> Finally I can confirm and reproduce when gateway mac ages out from mac
> address table(or flush) ovs starts to flood all ports and flows switch to
> software path. When It learn gateway mac address by any arp requests
> hardware offload works again.
>
> It seems increasing mac-aging on br-ex can be an option. What do you
> suggest permanent solution for this issue?
>

If you know well in advance of the destination Mac or the traffic pattern
then probably you can consider programming higher priority openflow rules
in br-ex ?

Thanks
Numan


> Thanks,
> Serhat
>
> On Thu, May 22, 2025 at 19:50 Serhat Rıfat Demircan <
> [email protected]> wrote:
>
>> No OVN, it is only OVS. oftrace says it flooding because "no learned MAC
>> for destination". Is this expected while there is existing traffic? And
>> another question is, can I prevent flooding? :)
>>
>> # ovs-appctl ofproto/trace br-int
>>> "in_port=4,ip,eth_src=fa:16:7e:e1:50:af,eth_dst=00:1c:73:aa:bb:cc,nw_src=X.X.X.X,nw_dst=Y.Y.Y.Y"
>>> Flow:
>>> ip,in_port=4,vlan_tci=0x0000,dl_src=fa:16:7e:e1:50:af,dl_dst=00:1c:73:aa:bb:cc,nw_src=X.X.X.X,nw_dst=Y.Y.Y.Y,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0,nw_frag=no
>>
>>
>> bridge("br-int")
>>> ----------------
>>>  0. priority 0, cookie 0x64ecae89c6f9a081
>>>     goto_table:58
>>> 58. priority 0, cookie 0x64ecae89c6f9a081
>>>     goto_table:60
>>> 60. in_port=4, priority 100, cookie 0x64ecae89c6f9a081
>>>     set_field:0x4->reg5
>>>     set_field:0x1->reg6
>>>     resubmit(,71)
>>> 71. ip,reg5=0x4,in_port=4,dl_src=fa:16:7e:e1:50:af,nw_src=X.X.X.X,
>>> priority 65, cookie 0x64ecae89c6f9a081
>>>     ct(table=72,zone=NXM_NX_REG6[0..15])
>>>     drop
>>>      -> A clone of the packet is forked to recirculate. The forked
>>> pipeline will be resumed at table 72.
>>>      -> Sets the packet to an untracked state, and clears all the
>>> conntrack fields.
>>
>>
>> Final flow:
>>> ip,reg5=0x4,reg6=0x1,in_port=4,vlan_tci=0x0000,dl_src=fa:16:7e:e1:50:af,dl_dst=00:1c:73:aa:bb:cc,nw_src=X.X.X.X,nw_dst=Y.Y.Y.Y,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0,nw_frag=no
>>> Megaflow:
>>> recirc_id=0,ct_state=-trk,eth,ip,in_port=4,dl_src=fa:16:7e:e1:50:af,nw_src=X.X.X.X,nw_proto=0,nw_frag=no
>>> Datapath actions: ct(zone=1),recirc(0x1)
>>
>>
>>
>>> ===============================================================================
>>> recirc(0x1) - resume conntrack with default ct_state=trk|new (use
>>> --ct-next to customize)
>>>
>>> ===============================================================================
>>
>>
>> Flow:
>>> recirc_id=0x1,ct_state=new|trk,ct_zone=1,eth,ip,reg5=0x4,reg6=0x1,in_port=4,vlan_tci=0x0000,dl_src=fa:16:7e:e1:50:af,dl_dst=00:1c:73:aa:bb:cc,nw_src=X.X.X.X,nw_dst=Y.Y.Y.Y,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0,nw_frag=no
>>
>>
>> bridge("br-int")
>>> ----------------
>>>     thaw
>>>         Resuming from table 72
>>> 72. ct_state=+new-est,ip,reg5=0x4, priority 74, cookie 0x64ecae89c6f9a081
>>>     resubmit(,73)
>>> 73. ct_state=+new-est,ip,reg5=0x4, priority 90, cookie 0x64ecae89c6f9a081
>>>     ct(commit,zone=NXM_NX_REG6[0..15])
>>>     drop
>>>      -> Sets the packet to an untracked state, and clears all the
>>> conntrack fields.
>>>     resubmit(,91)
>>> 91. priority 1, cookie 0x64ecae89c6f9a081
>>>     resubmit(,94)
>>> 94.
>>> reg6=0x1,dl_src=fa:16:7e:e1:50:af,dl_dst=00:00:00:00:00:00/01:00:00:00:00:00,
>>> priority 10, cookie 0x64ecae89c6f9a081
>>>     push_vlan:0x8100
>>>     set_field:4097->vlan_vid
>>>     output:1
>>
>>
>> bridge("br-ex")
>>> ---------------
>>>  0. in_port=2,dl_vlan=1, priority 4, cookie 0xd9b277145604416
>>>     set_field:4207->vlan_vid
>>>     NORMAL
>>>      -> no learned MAC for destination, flooding
>>
>>
>> Final flow:
>>> recirc_id=0x1,eth,ip,reg5=0x4,reg6=0x1,in_port=4,dl_vlan=1,dl_vlan_pcp=0,vlan_tci1=0x0000,dl_src=fa:16:7e:e1:50:af,dl_dst=00:1c:73:aa:bb:cc,nw_src=X.X.X.X,nw_dst=Y.Y.Y.Y,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0,nw_frag=no
>>> Megaflow:
>>> recirc_id=0x1,ct_state=+new-est-rel-rpl,eth,ip,in_port=4,dl_src=fa:16:7e:e1:50:af,dl_dst=00:1c:73:aa:bb:cc,nw_frag=no
>>> Datapath actions: ct(commit,zone=1),push_vlan(vid=111,pcp=0),1,5
>>
>>
>> Thanks,
>> Serhat
>>
>> On Thu, May 22, 2025 at 6:41 PM Numan Siddique <[email protected]> wrote:
>>
>>> On Thu, May 22, 2025 at 11:33 AM Serhat Rıfat Demircan via discuss
>>> <[email protected]> wrote:
>>> >
>>> > I think this is the actual flow change in ovs side. When br-ex(br-ex
>>> is external bridge, openstack is bond interface) is added as output
>>> interface it breaks offloading. Still do not know why it changes :) Do you
>>> have any idea why ovs decide to redirect traffic to external bridge?
>>> >
>>> > Offloaded flow:
>>> > ufid:10d312f5-7c7a-4bab-8594-090bbcd9af53,
>>> recirc_id(0x1),dp_hash(0/0),skb_priority(0/0),in_port(ens37f0npf0vf7),skb_mark(0/0),ct_state(0x22/0x2e),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),packet_type(ns=0/0,id=0/0),eth(src=fa:16:7e:e1:50:af,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(src=
>>> 0.0.0.0/0.0.0.0,dst=0.0.0.0/0.0.0.0,proto=0/0,tos=0/0,ttl=0/0,frag=no),
>>> packets:1325324668, bytes:4434013761329, used:3.390s, offloaded:yes, dp:tc,
>>> actions:push_vlan(vid=111,pcp=0),openstack
>>> >
>>> > Not offloaded flow:
>>> > ufid:10d312f5-7c7a-4bab-8594-090bbcd9af53,
>>> recirc_id(0x1),dp_hash(0/0),skb_priority(0/0),in_port(ens37f0npf0vf7),skb_mark(0/0),ct_state(0x22/0x2e),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),packet_type(ns=0/0,id=0/0),eth(src=fa:16:7e:e1:50:af,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(src=
>>> 0.0.0.0/0.0.0.0,dst=0.0.0.0/0.0.0.0,proto=0/0,tos=0/0,ttl=0/0,frag=no),
>>> packets:1387549198, bytes:4643405901604, used:0.000s, dp:tc,
>>> actions:push_vlan(vid=111,pcp=0),br-ex,openstack
>>>
>>> Maybe you run ofproto/trace on the sample traffic and see why it is
>>> outputting to br-ex ?
>>>
>>> Is it with OVN ?
>>>
>>> Thanks
>>> Numan
>>>
>>> >
>>> > Thanks,
>>> > Serhat
>>> >
>>> > On Wed, May 21, 2025 at 11:51 AM Serhat Rıfat Demircan <
>>> [email protected]> wrote:
>>> >>
>>> >> After little more digging, I see miss upcalls and flow modify logs
>>> like below while tc flow switching to not_in_hw. I also see similar upcall
>>> while switching back to in_hw.
>>> >>
>>> >>
>>> >> 2025-05-21T08:14:27.189Z|19748|dpif(handler3)|DBG|system@ovs-system:
>>> miss upcall:
>>> >>
>>> recirc_id(0),dp_hash(0),skb_priority(0),in_port(6),skb_mark(0),ct_state(0),ct_zone(0),ct_mark(0),ct_label(0),eth(src=fa:16:7e:75:94:76,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(src=IP_A,dst=IP_B,proto=6,tos=0,ttl=64,frag=no),tcp(src=52774,dst=6835),tcp_flags(ack)
>>> >>
>>> tcp,vlan_tci=0x0000,dl_src=fa:16:7e:75:94:76,dl_dst=00:1c:73:aa:bb:cc,nw_src=IP_A,nw_dst=IP_B,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=52774,tp_dst=6835,tcp_flags=ack
>>> tcp_csum:5abe
>>> >>
>>> >>
>>> 2025-05-21T08:14:27.189Z|104292|dpif(revalidator10)|DBG|system@ovs-system:
>>> put[modify] ufid:52588bba-04e5-43fa-b677-5a96dbd11f22
>>> recirc_id(0x5),dp_hash(0/0),skb_priority(0/0),in_port(4),skb_mark(0/0),ct_state(0x22/0xf),ct_zone(0x1/0),ct_mark(0/0),ct_label(0/0),ct_tuple4(src=IP_C/
>>> 0.0.0.0,dst=IP_D/0.0.0.0
>>> ,proto=6/0,tp_src=58586/0,tp_dst=6821/0),eth(src=fa:16:7e:e1:50:af,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(src=IP_C/
>>> 0.0.0.0,dst=IP_D/0.0.0.0,proto=6/0,tos=0/0,ttl=64/0,frag=no),tcp(src=58586/0,dst=6821/0),tcp_flags(0/0),
>>> actions:push_vlan(vid=111,pcp=0),1,5
>>> >>
>>> >> On Tue, May 20, 2025 at 7:49 PM Ilya Maximets <[email protected]>
>>> wrote:
>>> >>>
>>> >>> On 5/20/25 4:32 PM, Serhat Rıfat Demircan wrote:
>>> >>> > Yes, statistics are updated.
>>> >>> >
>>> >>> > # ovs-appctl dpctl/dump-flows type=offloaded | grep
>>> dst=00:1c:73:aa:bb:cc
>>> >>> >
>>> recirc_id(0x5),in_port(4),ct_state(+est-rel+rpl-inv+trk),ct_zone(0x1),ct_mark(0),eth(src=fa:16:7e:e1:50:af,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(frag=no),
>>> packets:222, bytes:30340, used:0.170s, actions:push_vlan(vid=111,pcp=0),5
>>> >>> >
>>> recirc_id(0x5),in_port(4),ct_state(+est-rel-rpl+trk),eth(src=fa:16:7e:e1:50:af,dst=00:1c:73:aa:bb:cc),eth_type(0x0800),ipv4(frag=no),
>>> packets:54220862, bytes:182391451911, used:0.170s,
>>> actions:push_vlan(vid=111,pcp=0),5
>>> >>>
>>> >>> Then one of the options would be to turn on debug logging and try
>>> >>> and catch the moment the flow actions change, and then correlate the
>>> >>> change with some other events in the log.  I'd suggest to start with:
>>> >>>   ovs-appctl vlog/set ofproto_dpif_xlate:file:dbg dpif:file:dbg
>>> >>>
>>> >>> Best regards, Ilya Maximets.
>>> >>>
>>> >>> >
>>> >>> > On Tue, May 20, 2025 at 3:39 PM Ilya Maximets <[email protected]
>>> <mailto:[email protected]>> wrote:
>>> >>> >
>>> >>> >     On 5/20/25 2:20 PM, Serhat Rıfat Demircan wrote:
>>> >>> >     > Redirecting to br-ex happens even if there is a single
>>> hardware offloaded port on hypervisor. Still can't find the actual reason.
>>> >>> >     > Increasing mac-aging-time and mac-table-size did not help
>>> also.
>>> >>> >     >
>>> >>> >     > By the way, it is bidirectional storage(ceph) traffic.
>>> >>> >
>>> >>> >     Is statistics on the datapath flows properly updated?
>>> >>> >     i.e. if you watch 'ovs-appctl dpctl/dump-flows', do you see
>>> stats
>>> >>> >     properly incremented when the flow is offloaded?
>>> >>> >
>>> >>> >     >
>>> >>> >     >
>>> >>> >     >
>>> >>> >     > On Wed, May 14, 2025 at 1:39 PM Ilya Maximets <
>>> [email protected] <mailto:[email protected]> <mailto:
>>> [email protected] <mailto:[email protected]>>> wrote:
>>> >>> >     >
>>> >>> >     >     On 5/8/25 4:15 PM, Serhat Rıfat Demircan via discuss
>>> wrote:
>>> >>> >     >     > Hello Everyone,
>>> >>> >     >     >
>>> >>> >     >     > I've been testing OVS hardware offloaded ports with
>>> Openstack for a while.
>>> >>> >     >     > I have ConnectX-5 and ConnectX-6 cards in my lab.
>>> Iperf tests are looking
>>> >>> >     >     > promising, but when I try to use hardware offloaded
>>> ports for krbd traffic,
>>> >>> >     >     > after some time, traffic falls back to the software
>>> path. Another interesting
>>> >>> >     >     > thing for me is without changing anything, it can also
>>> switch back to the
>>> >>> >     >     > hardware path. I could not find the real reason.
>>> >>> >     >     >
>>> >>> >     >     > I'm not sure if this is a configuration issue or if
>>> I'm hitting to cards limit.
>>> >>> >     >     > If any of you guys are experienced with this all ideas
>>> are more than welcome.
>>> >>> >     >     >
>>> >>> >     >     > Openstack version: Caracal
>>> >>> >     >     > Operation System: Ubuntu 22.04
>>> >>> >     >     > OVS version: 3.3.0
>>> >>> >     >     >
>>> >>> >     >     > I see tc flow change:
>>> >>> >     >     >
>>> >>> >     >     > *From Offloaded:*
>>> >>> >     >     > $ tc filter show dev ens37f0npf0vf6 ingress
>>> >>> >     >     > filter protocol ip pref 2 flower chain 0
>>> >>> >     >     > filter protocol ip pref 2 flower chain 0 handle 0x1
>>> >>> >     >     >   dst_mac 00:1c:73:aa:bb:cc
>>> >>> >     >     >   src_mac fa:16:7e:2e:8c:f0
>>> >>> >     >     >   eth_type ipv4
>>> >>> >     >     >   ip_flags nofrag
>>> >>> >     >     >   skip_sw
>>> >>> >     >     >   in_hw in_hw_count 1
>>> >>> >     >     > action order 1: vlan  push id 111 protocol 802.1Q
>>> priority 0 pipe
>>> >>> >     >     > index 4 ref 1 bind 1
>>> >>> >     >     > no_percpu
>>> >>> >     >     > used_hw_stats delayed
>>> >>> >     >     >
>>> >>> >     >     > action order 2: mirred (Egress Redirect to device
>>> openstack) stolen
>>> >>> >     >     > index 4 ref 1 bind 1
>>> >>> >     >     > cookie 605b82e5b94ef3fa63c3e78349851a27
>>> >>> >     >     > no_percpu
>>> >>> >     >     > used_hw_stats delayed
>>> >>> >     >     >
>>> >>> >     >     > *To software path:*
>>> >>> >     >     > $ tc filter show dev ens37f0npf0vf6 ingress
>>> >>> >     >     > filter protocol ip pref 2 flower chain 0
>>> >>> >     >     > filter protocol ip pref 2 flower chain 0 handle 0x1
>>> >>> >     >     >   dst_mac 00:1c:73:aa:bb:cc
>>> >>> >     >     >   src_mac fa:16:7e:2e:8c:f0
>>> >>> >     >     >   eth_type ipv4
>>> >>> >     >     >   ip_flags nofrag
>>> >>> >     >     >   not_in_hw
>>> >>> >     >     > action order 1: vlan  push id 111 protocol 802.1Q
>>> priority 0 pipe
>>> >>> >     >     > index 4 ref 1 bind 1
>>> >>> >     >     > no_percpu
>>> >>> >     >     >
>>> >>> >     >     > action order 2: skbedit  ptype host pipe
>>> >>> >     >     > index 11 ref 1 bind 1
>>> >>> >     >     >
>>> >>> >     >     > action order 3: mirred (Ingress Mirror to device
>>> br-ex) pipe
>>> >>> >     >     > index 13 ref 1 bind 1
>>> >>> >     >     > cookie 5037716e444e83b81c4ef9844df2377d
>>> >>> >     >     > no_percpu
>>> >>> >     >     >
>>> >>> >     >     > action order 4: mirred (Egress Redirect to device
>>> openstack) stolen
>>> >>> >     >     > index 15 ref 1 bind 1
>>> >>> >     >     > cookie 5037716e444e83b81c4ef9844df2377d
>>> >>> >     >     > no_percpu
>>> >>> >     >
>>> >>> >     >     Here you can see that traffic is getting broadcasted on
>>> all ports in the
>>> >>> >     >     br-ex bridge, and since some of these ports are virtual,
>>> this operation
>>> >>> >     >     cannot be offloaded to hardware.
>>> >>> >     >
>>> >>> >     >     I would guess, after some time the FDB entry expires and
>>> OVS no longer
>>> >>> >     >     knows on which port the traffic supposed to be sent
>>> out.  Is that a
>>> >>> >     >     unidirection traffic?  i.e. are you also sending traffic
>>> in the opposite
>>> >>> >     >     direction?  If not, are you sending some periodic ARP
>>> requests for the
>>> >>> >     >     bridge to learn where the destination is?
>>> >>> >     >
>>> >>> >     >     If the traffic is bidirectional, then it might be a NIC
>>> driver/firmware
>>> >>> >     >     issue not providing updated stats.
>>> >>> >     >
>>> >>> >     >     Best regards, Ilya Maximets.
>>> >>> >     >
>>> >>> >
>>> >>>
>>> > _______________________________________________
>>> > discuss mailing list
>>> > [email protected]
>>> > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
>>>
>>
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